PEDIATRICS Vol. 106 No. 1 July 2000, pp. 40-44
Adult Female Hip Bone Density Reflects
Teenage Sports-Exercise Patterns But Not Teenage Calcium Intake
Received Jun 1, 1999; accepted Oct 15, 1999.
Tom Lloyd*, Vernon M. Chinchilli*, Nan Johnson-Rollings*, Kessey
Kieselhorst , Douglas F. Eggli§, and Robert Marcus
From the Departments of * Health Evaluation Sciences, Clinical
Nutrition, and § Radiology, Pennsylvania State University,
College of Medicine, Hershey, Pennsylvania; and Department
of Medicine, Stanford University and Veterans Affairs Medical
Center, Palo Alto, California.
Objective. To examine how cumulative teenage sports histories
and time-averaged teenage calcium intake are related to total
body bone mineral gain between ages 12 and 18 years
and to proximal femur bone mineral density (BMD) at age 18 years.
Design. Longitudinal.
Setting. University Hospital and local suburban community
in Central Pennsylvania.
Study Participants. Eighty-one white females in the ongoing
Penn State Young Women's Health Study.
Outcome Measures. Total body and proximal femur (hip) bone
measurements by dual energy radiograph absorptiometry; nutrient
intakes, including calcium, from 33 days of prospective food
records collected at regular intervals between ages 12 and
18 years; and self-reported sports-exercise scores between
ages 12 and 18 years.
Results. Cumulative sports-exercise scores between ages
12 and 18 years were associated with hip BMD at age
18 years (r = .42) but were not related to total
body bone mineral gain. Time-averaged daily calcium intake, which
ranged from 500 to 1500 mg/day in this cohort was not
associated with hip BMD at age 18 years, or with total body
bone mineral gain at age 12 through 18 years.
Conclusions. The amount of physical activity that distinguishes
a primarily sedentary teenager from one who engages in some form
of exercise on a nearly daily basis is related to a significant
increase in peak hip BMD. Key words: peak hip bone
density, teenage sport histories, osteoporosis prevention.